This grant application is in response to RFA-NHLBI-DLC-79-G-C and requests support for an on-going research project directed towards studies on tracheobronchial mucous glycoproteins (MGPs) from the pig. Tracheobronchial secretions from the healthy human subject are difficult to obtain in sufficient amount for detailed chemical studies. The pig has a well-developed tracheobronchial system closely resembling that of the human and both secrete MGPs which have very similar chemical compositions and immunochemical properties. Presently, detailed compositional and structural analyses of MGPs from pig salivary glands, stomach and gallbladder are available. These tissues, like the tracheobronchial epithelial lining, secrete blood-group active MGPs. A comparison of the chemistry and immunochemical properties of MGPs from different tissues of the same species should prove useful in extrapolating to the human secretions. Compositional analysis, structural characterization and immunochemical properties of the pig tracheal MGPs will be determined. Biopsy samples obtained by fiberoptic bronchoscopy will be maintained in culture and the incorporation to (3H)-glucosamine, (3H)-fucose and (35S)-sulfate into MGP will be followed and compared with MGP isolated from the tracheal lining. Analytical and immunochemical procedures and tissue culture methods necessary to carry out the research are currently in use in our laboratory. These methods include gas chromatography, high performance liquid chromatography, gas chromatography/mass spectrometry, methylation analysis, blood grouping assays, specific exo- and endo-glycosidases, as well as the use of lectins and antibodies.